Milling cutter



BITCHIE I?. DEWEY, F ROCKFORD, ILLIN vPATENT OFFICE.

OIS, ASSIGNOR, BY MESNE ASSIGNMENTS,

TO BARBER-COLMAN COMPANY, OF ROCKFORD, ILLINOIS, A CORPORATION 0F ILLINOIS.

MILLING Application fil-ed November The invention relates to milling cutters ot the type commonly known as hollow mills and end mills; and it has tor its aim the provision ol:l a milling cutter ofi this class which is effectual from an operative standpoint and is at the saine time capable of being economi-cally manufactured and used.

With this aim in view, the object of the invention is to produce a milling cutter ot U the inserted tooth type having blades mounted for adjust-ment in a cylindrical head or body so that the blades may be resharpened until substantially consumed in use, the construction be-ing suoli that notwithstanding I5 such adjustment the cutting size or diameter of the tool may be maintained uniform.

A further object is to provide a construction for vthe tool .such asto enable its manufacture on an exceedingly practical basis.

The objects ot the invention thus generally stated, together with other and ancillary advantages, are attained by the construction and arrangement illustrated in the accomp-anying drawings forming part hereot. In

such drawings I have shown a cutter of the hollow mill type, but it will be apparent that the invention is not limited to a cutter designed for any speciiic purpose and that various changes in form, construction and arrangement may be made by those skilled in the art Without departing from the spirit and scope of the invention as expressed in the appended claim.

Figure 1 of the drawings is an elevational view of a cutter constructed in accordance with my invention. Fig. 2 is an end view of the same. Fig. 3 is a transverse sectional view taken in the plane of line 3--3 of Fig.

1. Fig. L1 is a similar view taken in the plane of line 1 -4l of Fig. 1. Fig. 5 is a fragmentary horizontal section taken in the plane of line 5-5 of Fig. 2.

The cutter comprises generally a shank 7 carrying a cylindrical body or head 8. 9.

designates the cutter blades which are mounted tor longitudinal adjustment in the head. These blades are moved simultaneously toward the lower end ot the head by means ot an adjusting collar 10, and the 5o blades are clamped in the desired position of adjustment by means of a locking ring 11.

The head 8 is formed integral with the shank 7 and at spaced intervals about its axis is provided with a plurality (preterably an uneven number) of longitudinal CUTTER.

2, 1921. Serial No. 512,285.

slots 12 for the reception of the blades 9. rlhe body has a central or axial bore 13 therein into which the inner edges of the blades project. rFor holding said blades against outward movement in the slots 12 im and ,tor guiding them in their longitudinal movemenathey are provided with ribs 14 upon one side engaging in complementary grooves 15 in the adjacent side walls of the slots. These ribs and grooves, as shown in Gf Figs. 2 and are inclined to a slight extent with reference to the axis of the cutter. Herein they are shown as being inclined'inwardly. so that 'as the'blades are moved downwardly in their slots, it will be apparent that they also move inwardly as guided by said ribs and grooves. The inner edges oi the blades are tapered or inclined outwardlyvv and upwardly as shown clearly in Fig; 5, at an angle somewhat less than that oi the guiding means. By this construction, a clearance is maintained at all times between the work and the edges of the blades adjacent thereto, and a cutting diameter of uniform size may be maintained notwithstanding the adjustment ot the blades to compensate for the loss o't' metal due to frequent re-grinding.' It will be noted that the blades are made of substantial length and that the greater portion thereof is capable ot use. Thus, the cutter may be used for an exceedingly long time without necessitating the replacement of the blades.

The exterior of the body or head 8 of the cutter is threaded as at 16 for engagement 90 by the internal threads formed upon the adjusting collar or ring 10; and the lower end or nose oi? the body is tapered and provided with screw threads 17 for enga-gement by the internally threaded locking ring 11. In order that the adjusting ring may engage with the blades 9 to move them downwardly in their slots, they are provided with portions or ears 18 projecting outwardly beyond the periphery of the body. By reason ot' 10o the fact that the head is slotted, it is capable of yielding under the action of the lock# ing ring 11 so as to clamp effectively the blades in the desired position of adjustment. rlhe ring 10 is provided with a dowel point 105 screw 19 which is adapted to engage in any one of the slots 12 to maintain the ring in its adjusted position. Each of these rings is preferably provided with suitable apertures 20 in its periphery for the reception 110 lll of a suitable implement to facilitate the operation thereof.

In the manufacture of my improved cutter, the body is first threaded exteriorly and the rings fitted thereon.. A se ies of holes are then drilled in the nose of the body at equidistantly spaced points and at an angle corresponding to the desired angle of the grooves 15. These holes obviously lie along elements of a cone having its axis in common with the cutter. These holes are of the same radius as that of said groove. In the next operation, the body is bored centrally thereof to render it resilient under the action of the loc-hing ring 1l. Finally the slots l2 are cut so that one Wall thereof coincides exactly with the diameter of the holes previously drilled. Thus the grooves l5 are formed.

lt will be observed that l have provided a construction for milling cutt rs of the hollow mill type and the end mill type, Which is of a very eilicient and practical character. The parts are tapable of being quickly assembled and disassembled; the blades are readily adjustable by a simple manipulation of the adjusting collar, and

are firmly held in position by means of the guiding ribs and grooves and the locking ring ll. The blades are made of substantial length and a substantial portion thereof is capable of use so that the cutter is capable of operation for an exceptionally long time Without necessitating` a replacement of the blades; and as the ends of the blades become Worn and are reduced in size in 11e-sharpening, the adjustment of the blades to compensate for such decrease in size may be effected Without destroying the unformty of the cutting diameter of the mill. By the construction herein shown the internal eut- Vting diameter is maintained, but it will be obvious that by properly arranging the grooves and shaping the side edges of the blades, the outer cutting diameter may similarly .be maintained. .i

I claim as my invention:

A milling cutter comprising a cylindrical body of substantial length and having an axial bore extending substantially throughout the length thereof, said body being slotted longitudinally and having a plurality of blades inserted therein and having outwardly projecting portions extending beyond the periphery thereof, means for guiding said blades for longitudinal movement, means for moving said blades comprising a ring screw-threaded upon the exterior of the body and adapted to engage with said outwardly projecting portion, said ring having means adapted to engage with said slots to hold it in the desired position of adjustment, and means upon the nose of the body for clamping the blades in their slots.

In testimony whereof, I have hereunto set my hand.

RITCHIE P. DEWEY. 

